1. Field
The following description relates to a software-defined network (SDN) system and a method for implementing the SDN system which can increase scalability and manageability of a hierarchical SDN-based network by abstracting not only SDN controllers and SDN switches, but also hosts that are connected to said SDN controllers and SDN switches to create them as virtual machines.
2. Description of the Related Art
In a software-defined network (SDN), a network is divided into a transport plane (or a data plane) and a control plane, wherein the transport plane queries all decisions related to packet transmission to the control plane, thereby allowing for centralized control of both network architecture and packet flow via software installed on the control plane.
The current SDN technology is in progress of research and development regarding not only the construction of a large-scale SDN network, but also regarding the interworking between large-scale SDN networks.
However, as an SDN network is hierarchical, an existing SDN implementation method, according to which an SDN network is constructed by abstracting only switches and controllers but not hosts, may experience a significant degradation of scalability of the network because the information regarding hosts under control of upper-level controllers, specifically, the highest-level controller, is exponentially increased, which may cause network service disconnection and errors.